[Mesa-dev] [PATCH 2/9] meta: Refactor the BlitFramebuffer color CopyTexImage fallback.

[Ian Romanick]

On 04/08/2014 02:03 PM, Eric Anholt wrote:
> There shouldn't be anything special about copying out a subset of the src
> rb to a temp before texturing from it, so just do it when we're figuring
> out our src texture binding.
> 
> This drops Anuj's change to copy an extra border of 1 pixel around the src
> area.  I can't see how that change could be valid, and presumably if
> there's some filtering problem at edges we just need to set the right
> wrap mode.

A lot of Anuj's recent changes have been to fix failures in the the
desktop GL conformance tests.  It would be worth having Anuj verify that
this series doesn't regress anything there...

> ---
>  src/mesa/drivers/common/meta_blit.c | 77 +++++++++++++++++--------------------
>  1 file changed, 36 insertions(+), 41 deletions(-)
> 
> diff --git a/src/mesa/drivers/common/meta_blit.c b/src/mesa/drivers/common/meta_blit.c
> index c201521..a65fcb2 100644
> --- a/src/mesa/drivers/common/meta_blit.c
> +++ b/src/mesa/drivers/common/meta_blit.c
> @@ -389,6 +389,7 @@ blitframebuffer_texture(struct gl_context *ctx,
>        ctx->Texture.Unit[ctx->Texture.CurrentUnit].Sampler->Name : 0;
>     GLuint tempTex = 0;
>     struct gl_renderbuffer *rb = readAtt->Renderbuffer;
> +   struct temp_texture *meta_temp_texture;
>  
>     if (rb->NumSamples && !ctx->Extensions.ARB_texture_multisample)
>        return false;
> @@ -449,7 +450,38 @@ blitframebuffer_texture(struct gl_context *ctx,
>           }
>        }
>     } else {
> -      return false;
> +      GLenum tex_base_format;
> +      int srcW = abs(srcY1 - srcY0);
> +      int srcH = abs(srcY1 - srcY0);
> +      /* Fall back to doing a CopyTexSubImage to get the destination
> +       * renderbuffer into a texture.
> +       */
> +      if (rb->NumSamples > 1)
> +         return false;
> +
> +      if (do_depth) {
> +         return false;
> +      } else {
> +         meta_temp_texture = _mesa_meta_get_temp_texture(ctx);
> +         tex_base_format =
> +            _mesa_base_tex_format(ctx, rb->InternalFormat);
> +      }
> +
> +      srcLevel = 0;
> +      target = meta_temp_texture->Target;
> +      texObj = _mesa_lookup_texture(ctx, meta_temp_texture->TexObj);
> +
> +      _mesa_meta_setup_copypix_texture(ctx, meta_temp_texture,
> +                                       srcX0, srcY0,
> +                                       srcW, srcH,
> +                                       tex_base_format,
> +                                       filter);
> +
> +
> +      srcX0 = 0;
> +      srcY0 = 0;
> +      srcX1 = srcW;
> +      srcY1 = srcH;
>     }
>  
>     baseLevelSave = texObj->BaseLevel;
> @@ -601,7 +633,6 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
>                             GLbitfield mask, GLenum filter)
>  {
>     struct blit_state *blit = &ctx->Meta->Blit;
> -   struct temp_texture *tex = _mesa_meta_get_temp_texture(ctx);
>     struct temp_texture *depthTex = _mesa_meta_get_temp_depth_texture(ctx);
>     const GLint srcX = MIN2(srcX0, srcX1);
>     const GLint srcY = MIN2(srcY0, srcY1);
> @@ -663,7 +694,7 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
>      * BlitFramebuffer function.
>      */
>     if (use_glsl_version) {
> -      setup_glsl_blit_framebuffer(ctx, blit, NULL, tex->Target);
> +      setup_glsl_blit_framebuffer(ctx, blit, NULL, depthTex->Target);
>     }
>     else {
>        _mesa_meta_setup_ff_tnl_for_blit(&blit->VAO, &blit->VBO, 2);
> @@ -689,43 +720,7 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
>     }
>  
>     if (!use_glsl_version)
> -      _mesa_set_enable(ctx, tex->Target, GL_TRUE);
> -
> -   if (mask & GL_COLOR_BUFFER_BIT) {
> -      const struct gl_framebuffer *readFb = ctx->ReadBuffer;
> -      const struct gl_renderbuffer *colorReadRb = readFb->_ColorReadBuffer;
> -      const GLenum rb_base_format =
> -         _mesa_base_tex_format(ctx, colorReadRb->InternalFormat);
> -
> -      /* Using  the exact source rectangle to create the texture does incorrect
> -       * linear filtering along the edges. So, allocate the texture extended along
> -       * edges by one pixel in x, y directions.
> -       */
> -      _mesa_meta_setup_copypix_texture(ctx, tex,
> -                                       srcX - 1, srcY - 1, srcW + 2, srcH + 2,
> -                                       rb_base_format, filter);
> -      /* texcoords (after texture allocation!) */
> -      {
> -         verts[0].tex[0] = 1.0F;
> -         verts[0].tex[1] = 1.0F;
> -         verts[1].tex[0] = tex->Sright - 1.0F;
> -         verts[1].tex[1] = 1.0F;
> -         verts[2].tex[0] = tex->Sright - 1.0F;
> -         verts[2].tex[1] = tex->Ttop - 1.0F;
> -         verts[3].tex[0] = 1.0F;
> -         verts[3].tex[1] = tex->Ttop - 1.0F;
> -
> -         /* upload new vertex data */
> -         _mesa_BufferSubData(GL_ARRAY_BUFFER_ARB, 0, sizeof(verts), verts);
> -      }
> -
> -      _mesa_set_viewport(ctx, 0, dstX, dstY, dstW, dstH);
> -      _mesa_ColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
> -      _mesa_set_enable(ctx, GL_DEPTH_TEST, GL_FALSE);
> -      _mesa_DepthMask(GL_FALSE);
> -      _mesa_DrawArrays(GL_TRIANGLE_FAN, 0, 4);
> -      mask &= ~GL_COLOR_BUFFER_BIT;
> -   }
> +      _mesa_set_enable(ctx, depthTex->Target, GL_TRUE);
>  
>     if ((mask & GL_DEPTH_BUFFER_BIT) &&
>         _mesa_is_desktop_gl(ctx) &&
> @@ -783,7 +778,7 @@ _mesa_meta_BlitFramebuffer(struct gl_context *ctx,
>     }
>  
>     if (!use_glsl_version)
> -      _mesa_set_enable(ctx, tex->Target, GL_FALSE);
> +      _mesa_set_enable(ctx, depthTex->Target, GL_FALSE);
>  
>     _mesa_meta_end(ctx);
>  
>